PROJECT SUMMARY Funds are requested for the purchase of a 14.1 T magnet with an 89 mm bore and integrated field regulation to sweep the main field 1280 G and to purchase an integrated magic angle spinning (MAS) cryogenic system. The magnet and cryogenics will be vital parts of a 600 MHz DNP NMR system for DNP-enhanced solid state NMR spectroscopic studies of biomolecular systems and materials. This instrument will be part of the first large scale DNP NMR user facility within the U.S., and will be operated as part of the highly successful user program of the National High Magnetic Field Laboratory. This instrument will also serve as the focal point for developing RF probes to enhance the characterization of sensitivity-limited biomolecular systems such as membrane proteins, viral capsid assemblies, amyloid fibrils, and biofilms relevant to NIH funding. In addition, optimized techniques for sample preparation of these delicate samples will be refined. The need for a sweepable widebore 14.1 T magnet, as opposed to the conventional fixed-field magnet used in conventional ssNMR spectrometers, stems from a special need of the gyrotron-based DNP NMR experiment: being narrow-band devices, the sole way that the current generation of gyrotrons can accommodate the multitude of radicals that are demanded for DNP-enhanced biomolecular investigations is to have a capability to change the Larmor frequency of the electrons involved in the experiment. The cryogenic system is required to enable the lowest temperatures possible for both magic angle spinning and oriented biomolecular samples, as the DNP enhancement scales linearly with lower temperatures. The NMR user facilities of the NHMFL already support a broad range of NIH-funded research projects and in this proposal we describe sixteen NIH-funded projects that are at the forefront of developing and utilizing new ssNMR tools for structural biology and will directly benefit from the proposed instrument.